First n Digits of Pi

As far as we currently know, approximations for the mathematical constant pi (π) in the history of mathematics started surfacing with Ancient Babylonians, who found its correct truncation up to 1 decimal place. During the 5th century, the Chinese mathematician Zu Chongzhi raised it to 7 decimal places and from the 18th century onwards the number of correct pi decimal places has seen steady growth.

Since the middle of the 20th century, the approximation of pi has been the task of electronic digital computers. During the 2019 Pi Day on the 14th of March, the Japanese computer scientist Emma Haruka Iwao released the currently most accurate value of pi with more than 31.4 trillion digits, using 170 Terabytes of data.

Your task is to create a function that takes a positive integer n as an argument and returns the value of pi with its first n decimal digits.

Taylor series are usually used to get finer approximations. To make this challenge approachable to anyone, the following formula is suggested:

Examples

pi(1) ➞ "3.1"

pi(2) ➞ "3.14"

pi(30) ➞ "3.141592653589793238462643383279"

Notes

N/A